//CharTest.java
/*
char type.  
Program can input, store, process and output (individual) characters.
char constants denoted by single char within pair of single quotes:

'a'   //lowercase letters
'W'   //uppercase letters
'$'   //punctuation characters
'9'   //digit characters  '8' is not 8 is not "8" is not 8.0
' '   //blank (or space) character
'\n'  //newline escape sequence
'\t'  //tab
'\\'  //backslash

'ab' is a syntax error.
"ab" is a string.

  'a'  is different than and incompatible with "a"
  char                                         String

chars are 2-byte Unicode characters (65000 of them, including 20000 
Chinese/Kanji and 10000 Hangul, plus all the alphabets: Greek, Cyrillic,
Arabic, Hebrew, Thai, Hindi, etc

Unlike a String, can switch on a char and use == != < <= etc.
*/

import java.awt.*;
import javax.swing.*;

public class CharTest extends JApplet {    

    public static void main(String[] argv) {
    //public void init() {

	char c;      //variable of type char
	String input;

	c = '$';     //assign it a char value
	JOptionPane.showMessageDialog(null, "It's now " + c);
	
	if (c != 'A')   //can use == != < etc with chars
	    JOptionPane.showMessageDialog(null, "It's not an A");

	input = JOptionPane.showInputDialog( "Enter a character" );
	//String is like an array. elements are chars.
	c = input.charAt(0);  //first character of String

	JOptionPane.showMessageDialog(null, "Thanks for " + c);

	//syntax errors:
	//c = 'ab';   //can only be one char in the single quotes.
	//c = "ab";   //can't assign a String to a char.
	//c = "a";    //it's a String.  can't assign a String to a char.
	String s;
	//s = 'W';    //can't assign a char to a String

	char c1, c2;
	c1 = 'X'; 
	c2 = c1;
	if (c1 == c2)
	    JOptionPane.showMessageDialog(null, "They equal");

	switch (c1) {    //switch on a char
	case 'w': 
	    JOptionPane.showMessageDialog(null, "this won't happen");
	    break;
	case 'X':
	    JOptionPane.showMessageDialog(null, "switching on a char X");
	    break;
	}

	//real world data that can be char:
	char maritalStatus, sex, grade, middleInitial, yesNo, trueFalse;

    }
}